.bigbox{
  width: 100%;
  height: 100%;
}

.contents{
    width: 1000px;
    height: 600px;
    background: #000;
    margin: 0 auto;
}

.contents2{
    width: 1000px;
    height: 200px;
    margin: 0 auto;
    margin-top: 30px;
}

.but0{
    width: 100px;
    height: 50px;
    float: left;
    color: #fff;
    text-align: center;
    line-height: 50px;
    background: red;
    margin-right: 30px;
}

.but1{
    width: 30%;
    height: 50px;
    float: left;
    color: #fff;
    text-align: center;
    line-height: 50px;
    background: skyblue;
}

.but2{
    width: 30%;
    height: 50px;
    float: right;
    color: #fff;
    text-align: center;
    line-height: 50px;
    background: skyblue;
}